io.eezo.core.html

An attribute. The value is optional rather than a plain AttrValue so that value := "" and disabled stay distinct: None renders the bare name, Some(Literal("")) renders value="". Collapsing the two would make an empty text input indistinguishable from a boolean flag.

The constructor is package private, the same shape as Html.Text, so := on an AttrName is the only way to build one from outside io.eezo.core.html, while the pattern match that the differ in modules/live needs still compiles from anywhere. Pairing a name of a call site's own choosing with an AttrValue.Link is what would otherwise reopen the set of url bearing names that Attrs closes.

An attribute name, waiting for its value.

sealed rather than final so that UrlAttrName can add the one arm the url bearing names need, and no view file can invent a fourth kind of attribute name from outside this file.

What an attribute carries.

Two cases because a mount has to tell them apart: text is finished, and a Url is a value Route.under can still move. Only the url bearing names build a Link, so the arm exists exactly where prefixing an address is meaningful.

The attribute names, qualified rather than wildcard imported, because they collide with the tags on title, style, label, form, value, name, data and span.

The three Scala keywords are spelled cls, tpe and htmlFor rather than backticked, because a backticked `for` is a papercut on every label in every form, and forms are the framework's most written markup.

eezo's HTML node tree.

Four cases and no more. There is no Comment case, because nothing eezo renders emits one and Html.raw covers it if something ever does, and no Doctype case, because Html.doctype is a Raw the caller puts first. A case that may legally appear at exactly one position in the tree is a case every match in modules/live has to handle and then ignore.

A list child's identity, which modules/live needs to tell one row from another across a diff. It reaches Html.Element.key through its own type rather than through an intercepted attribute name, because interception by string is exactly the convention-not-type problem the field exists to avoid.

A tag name, applied to build an element.

The tags. Wildcard imported, because a view file mentions far more distinct tags than distinct attributes; Attrs stays qualified, because the two collide on title, style, label, form, value, name, data and span.

Coverage is the floor the seven derived routes need: document, structure, text, lists, forms, media and tables, which is everything they render.

A URL a page emits, in the two kinds a mount has to tell apart.

A String in an href is a finished address, and finished is exactly what a mounted application's own links are not: Route.under("/admin") moves the route and the page has no way to hear about it. The two cases are that difference, made a type rather than a convention, so that relocation is decided where the URL is written instead of guessed where it is served.

There is no third case for "resolved". Prefixing a Mounted keeps it Mounted, because a set of routes can be mounted again, and a case saying the work is done would have to be undone by the next layer.

An attribute name whose value is an address: href, action, src.

Separate from AttrName because a Url means something only where a browser will follow it. Restricting the arm to these three is what makes Attrs.cls := Url.Mounted("/posts") a compile error rather than a class attribute that quietly moves under a mount. The constructor stays private[html] so Attrs is the one list that decides which names carry a Url, and the constructors of Attr and AttrValue.Link are package private for the same reason: either of them left public would let a call site outside io.eezo.core.html pair a name of its own with an AttrValue.Link, minting one outright or lifting one out of an href attribute it had just built, and so mint a fourth url bearing name that a mount would then rewrite.

Everything a tag accepts as an argument.

A union rather than a Modifier trait with a given Conversion: under this build's own -feature -Werror, a conversion is a hard error at every use site unless the view file opens with import scala.language.implicitConversions, and a language import in every view file is the opposite of effortless.

Users cannot add their own arm today. That loss is recoverable: widening a union parameter is both source and binary compatible, so | Modifier can be added the day somebody needs it.

Builds a list child's Key.